In active driver assistance systems, for example lane detection and lane change warning systems, traffic sign recognition systems or emergency braking systems, visual sensors, for example cameras, are used to provide input data for the relevant systems. The visual input data are used in various algorithms that initiate corresponding reactions of the vehicle, for example vehicle steering, vehicle braking or feedback from a human-machine interface (HMI).
In order to test such active driver assistance systems, it is necessary to operate the accordingly equipped vehicles under real conditions of use, in which case an interaction with real road markings, traffic signs and third-party vehicles is required, in particular. This results in a considerable outlay and in a high degree of complexity of the respective test procedures. Only performing tests on a test bench (for example in “hardware-in-the-loop” test benches) proves to be insufficient since the entire vehicle system, its interaction with the environment (for example under different weather conditions such as sun or rain or in the case of different road surfaces) and the interaction with the driver must be taken into account for a reliable test of the driver assistance system.
In the case of a lane departure assistant, a test under all possible scenarios in the real world or on a test track with all special road markings is required, in principle, for example.
In the case of traffic sign recognition, speed limit signs are captured using a front camera and the respectively prescribed maximum speeds are identified, whereupon further actions of the vehicle can be initiated. In principle, such a system has to be tested for all conventional traffic signs, which can be carried out either by performing worldwide test drives, or using a test track provided with all conventional traffic signs.
In the case of emergency braking systems, objects on a route ahead of the vehicle are detected, and the brakes of the vehicle are activated in order to avoid, or at least reduce, a collision. Such systems are typically tested on test tracks using particular obstacles, for example foam blocks having the shape of a vehicle, such obstacles being either static or (if movable objects are implemented) complex to produce and control.
U.S. 2015/0149031 A1 discloses, inter alia, a method for testing a vehicle, a test control unit generating or playing back a virtual world which contains both a virtual vehicle state and a virtual vehicle environment. In this case, a driving state actuator generates the instantaneous vehicle state in the virtual world and the instantaneous vehicle environment by introducing additional forces or torques into the real vehicle, with the result that the real vehicle on the real test track experiences the vehicle state and the vehicle environment from the virtual world.